docs: def parse(self, *args, **kw):
          """Parse command line, fill `fuse_args` attribute."""
  
          ev = 'errex' in kw and kw.pop('errex')
          if ev and not isinstance(ev, int):
              raise TypeError("error exit value should be an integer")
  
          try:
              self.cmdline = self.parser.parse_args(*args, **kw)
          except OptParseError:
            if ev:
                sys.exit(ev)
            raise
  
          return self.fuse_args